1 /*- 2 * Copyright (c) 2010 Isilon Systems, Inc. 3 * Copyright (c) 2010 iX Systems, Inc. 4 * Copyright (c) 2010 Panasas, Inc. 5 * Copyright (c) 2013, 2014 Mellanox Technologies, Ltd. 6 * All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice unmodified, this list of conditions, and the following 13 * disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 #ifndef _LINUXKPI_LINUX_SYSFS_H_ 30 #define _LINUXKPI_LINUX_SYSFS_H_ 31 32 #include <sys/types.h> 33 #include <sys/sysctl.h> 34 #include <sys/errno.h> 35 36 #include <linux/kobject.h> 37 #include <linux/stringify.h> 38 #include <linux/mm.h> 39 40 struct sysfs_ops { 41 ssize_t (*show)(struct kobject *, struct attribute *, char *); 42 ssize_t (*store)(struct kobject *, struct attribute *, const char *, 43 size_t); 44 }; 45 46 struct attribute_group { 47 const char *name; 48 mode_t (*is_visible)(struct kobject *, 49 struct attribute *, int); 50 struct attribute **attrs; 51 }; 52 53 #define __ATTR(_name, _mode, _show, _store) { \ 54 .attr = { .name = __stringify(_name), .mode = _mode }, \ 55 .show = _show, .store = _store, \ 56 } 57 #define __ATTR_RO(_name) { \ 58 .attr = { .name = __stringify(_name), .mode = 0444 }, \ 59 .show = _name##_show, \ 60 } 61 #define __ATTR_WO(_name) __ATTR(_name, 0200, NULL, _name##_store) 62 #define __ATTR_RW(_name) __ATTR(_name, 0644, _name##_show, _name##_store) 63 #define __ATTR_NULL { .attr = { .name = NULL } } 64 65 #define ATTRIBUTE_GROUPS(_name) \ 66 static struct attribute_group _name##_group = { \ 67 .name = __stringify(_name), \ 68 .attrs = _name##_attrs, \ 69 }; \ 70 static const struct attribute_group *_name##_groups[] = { \ 71 &_name##_group, \ 72 NULL, \ 73 } 74 75 /* 76 * Handle our generic '\0' terminated 'C' string. 77 * Two cases: 78 * a variable string: point arg1 at it, arg2 is max length. 79 * a constant string: point arg1 at it, arg2 is zero. 80 */ 81 82 static inline int 83 sysctl_handle_attr(SYSCTL_HANDLER_ARGS) 84 { 85 struct kobject *kobj; 86 struct attribute *attr; 87 const struct sysfs_ops *ops; 88 char *buf; 89 int error; 90 ssize_t len; 91 92 kobj = arg1; 93 attr = (struct attribute *)(intptr_t)arg2; 94 if (kobj->ktype == NULL || kobj->ktype->sysfs_ops == NULL) 95 return (ENODEV); 96 buf = (char *)get_zeroed_page(GFP_KERNEL); 97 if (buf == NULL) 98 return (ENOMEM); 99 ops = kobj->ktype->sysfs_ops; 100 if (ops->show) { 101 len = ops->show(kobj, attr, buf); 102 /* 103 * It's valid to not have a 'show' so just return an 104 * empty string. 105 */ 106 if (len < 0) { 107 error = -len; 108 if (error != EIO) 109 goto out; 110 buf[0] = '\0'; 111 } else if (len) { 112 len--; 113 if (len >= PAGE_SIZE) 114 len = PAGE_SIZE - 1; 115 /* Trim trailing newline. */ 116 buf[len] = '\0'; 117 } 118 } 119 120 /* Leave one trailing byte to append a newline. */ 121 error = sysctl_handle_string(oidp, buf, PAGE_SIZE - 1, req); 122 if (error != 0 || req->newptr == NULL || ops->store == NULL) 123 goto out; 124 len = strlcat(buf, "\n", PAGE_SIZE); 125 KASSERT(len < PAGE_SIZE, ("new attribute truncated")); 126 len = ops->store(kobj, attr, buf, len); 127 if (len < 0) 128 error = -len; 129 out: 130 free_page((unsigned long)buf); 131 132 return (error); 133 } 134 135 static inline int 136 sysfs_create_file(struct kobject *kobj, const struct attribute *attr) 137 { 138 struct sysctl_oid *oid; 139 140 oid = SYSCTL_ADD_OID(NULL, SYSCTL_CHILDREN(kobj->oidp), OID_AUTO, 141 attr->name, CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_MPSAFE, kobj, 142 (uintptr_t)attr, sysctl_handle_attr, "A", ""); 143 if (!oid) { 144 return (-ENOMEM); 145 } 146 147 return (0); 148 } 149 150 static inline void 151 sysfs_remove_file(struct kobject *kobj, const struct attribute *attr) 152 { 153 154 if (kobj->oidp) 155 sysctl_remove_name(kobj->oidp, attr->name, 1, 1); 156 } 157 158 static inline int 159 sysfs_create_link(struct kobject *kobj __unused, 160 struct kobject *target __unused, const char *name __unused) 161 { 162 /* TODO */ 163 164 return (0); 165 } 166 167 static inline int 168 sysfs_create_files(struct kobject *kobj, const struct attribute * const *attrs) 169 { 170 int error = 0; 171 int i; 172 173 for (i = 0; attrs[i] && !error; i++) 174 error = sysfs_create_file(kobj, attrs[i]); 175 while (error && --i >= 0) 176 sysfs_remove_file(kobj, attrs[i]); 177 178 return (error); 179 } 180 181 static inline void 182 sysfs_remove_files(struct kobject *kobj, const struct attribute * const *attrs) 183 { 184 int i; 185 186 for (i = 0; attrs[i]; i++) 187 sysfs_remove_file(kobj, attrs[i]); 188 } 189 190 static inline int 191 sysfs_create_group(struct kobject *kobj, const struct attribute_group *grp) 192 { 193 struct attribute **attr; 194 struct sysctl_oid *oidp; 195 196 /* Don't create the group node if grp->name is undefined. */ 197 if (grp->name) 198 oidp = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(kobj->oidp), 199 OID_AUTO, grp->name, CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, grp->name); 200 else 201 oidp = kobj->oidp; 202 for (attr = grp->attrs; *attr != NULL; attr++) { 203 SYSCTL_ADD_OID(NULL, SYSCTL_CHILDREN(oidp), OID_AUTO, 204 (*attr)->name, CTLTYPE_STRING|CTLFLAG_RW|CTLFLAG_MPSAFE, 205 kobj, (uintptr_t)*attr, sysctl_handle_attr, "A", ""); 206 } 207 208 return (0); 209 } 210 211 static inline void 212 sysfs_remove_group(struct kobject *kobj, const struct attribute_group *grp) 213 { 214 215 if (kobj->oidp) 216 sysctl_remove_name(kobj->oidp, grp->name, 1, 1); 217 } 218 219 static inline int 220 sysfs_create_groups(struct kobject *kobj, const struct attribute_group **grps) 221 { 222 int error = 0; 223 int i; 224 225 if (grps == NULL) 226 goto done; 227 for (i = 0; grps[i] && !error; i++) 228 error = sysfs_create_group(kobj, grps[i]); 229 while (error && --i >= 0) 230 sysfs_remove_group(kobj, grps[i]); 231 done: 232 return (error); 233 } 234 235 static inline void 236 sysfs_remove_groups(struct kobject *kobj, const struct attribute_group **grps) 237 { 238 int i; 239 240 if (grps == NULL) 241 return; 242 for (i = 0; grps[i]; i++) 243 sysfs_remove_group(kobj, grps[i]); 244 } 245 246 static inline int 247 sysfs_merge_group(struct kobject *kobj, const struct attribute_group *grp) 248 { 249 250 /* Really expected behavior is to return failure if group exists. */ 251 return (sysfs_create_group(kobj, grp)); 252 } 253 254 static inline void 255 sysfs_unmerge_group(struct kobject *kobj, const struct attribute_group *grp) 256 { 257 struct attribute **attr; 258 struct sysctl_oid *oidp; 259 260 SYSCTL_FOREACH(oidp, SYSCTL_CHILDREN(kobj->oidp)) { 261 if (strcmp(oidp->oid_name, grp->name) != 0) 262 continue; 263 for (attr = grp->attrs; *attr != NULL; attr++) { 264 sysctl_remove_name(oidp, (*attr)->name, 1, 1); 265 } 266 } 267 } 268 269 static inline int 270 sysfs_create_dir(struct kobject *kobj) 271 { 272 struct sysctl_oid *oid; 273 274 oid = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(kobj->parent->oidp), 275 OID_AUTO, kobj->name, CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, kobj->name); 276 if (!oid) { 277 return (-ENOMEM); 278 } 279 kobj->oidp = oid; 280 281 return (0); 282 } 283 284 static inline void 285 sysfs_remove_dir(struct kobject *kobj) 286 { 287 288 if (kobj->oidp == NULL) 289 return; 290 sysctl_remove_oid(kobj->oidp, 1, 1); 291 } 292 293 static inline bool 294 sysfs_streq(const char *s1, const char *s2) 295 { 296 int l1, l2; 297 298 l1 = strlen(s1); 299 l2 = strlen(s2); 300 301 if (l1 != 0 && s1[l1-1] == '\n') 302 l1--; 303 if (l2 != 0 && s2[l2-1] == '\n') 304 l2--; 305 306 return (l1 == l2 && strncmp(s1, s2, l1) == 0); 307 } 308 309 static inline int 310 sysfs_emit(char *buf, const char *fmt, ...) 311 { 312 va_list args; 313 int i; 314 315 if (!buf || offset_in_page(buf)) { 316 pr_warn("invalid sysfs_emit: buf:%p\n", buf); 317 return (0); 318 } 319 320 va_start(args, fmt); 321 i = vscnprintf(buf, PAGE_SIZE, fmt, args); 322 va_end(args); 323 324 return (i); 325 } 326 327 static inline int 328 sysfs_emit_at(char *buf, int at, const char *fmt, ...) 329 { 330 va_list args; 331 int i; 332 333 if (!buf || offset_in_page(buf) || at < 0 || at >= PAGE_SIZE) { 334 pr_warn("invalid sysfs_emit: buf:%p at:%d\n", buf, at); 335 return (0); 336 } 337 338 va_start(args, fmt); 339 i = vscnprintf(buf + at, PAGE_SIZE - at, fmt, args); 340 va_end(args); 341 342 return (i); 343 } 344 345 #define sysfs_attr_init(attr) do {} while(0) 346 347 #endif /* _LINUXKPI_LINUX_SYSFS_H_ */ 348